Merfolk

@naixin In my limited experience with Merfolk, I've found that Walk itself is just great. It's so good that you often win when you draw it, and lose much more often when you don't. This deck goes lethal on turn 4-6 quite often. While that would be impressive in any other format, it makes Merfolk solidly "mid-range" by vintage standards. In my experience, that means that in many games this deck wins or loses by a single turn. Therefore, Walk is one of the best cards in the deck, as I think you've correctly recognized. However, a second, worse Walk seems like diminishing returns to me, precisely because Walk is so good. If you are going to tutor, just get Walk. If you natural draw one of the two, you want it to be Walk. And because Walk so often wins by itself, you rarely need a second. If you did need a second, then that means that the same job could have been done in most cases by an accelerated clock. So in most cases, a Lord would have been as good, and Lords are much better to draw in an opening hand than is Mastery. While we can't say that adding Mastery is strictly worse, I think we can rightly predict that testing would show that it loses more games than it wins if added.

The first card I would add to the list is Mox Pearl, if I had space. It lets you drop damping sphere on T1 against shops at a much greater rate, as well as gets you up to Hurk a turn quicker against Paradoxical. I reckon it improves our post board rates a lot, because it lets us get Priest and Null rod and Hurk and Flux and Damping on the table much quicker. (We are at 2 mana or more 10% more often on T1 by adding Pearl.)

Brainstorm looks nice too. I would have to test on that one. 4 fetches isn't a ton. But I reckon this comes down to using mana efficiently. It feels like this deck will already spend almost all of it's mana every turn?

Lastly, Chart a Course is a new card since the last time this deck was good. It at least needs a look. Part of me doubts it gets in, somehow, just because of the 2 mana cost? But I also wouldn't be surprised to see lists that run it in multiples either. It does not create damage, but lets us toss our extra lands late if we need to in favor of more useful resources. So it's overall effect is likely to slow our clock somewhat, but to give the deck more finish to power through a rain of Swords against Xerox on turns 5-9.

@topical_island I’ve considered adding a lotus petal for the explosive start potential well. I think we should be at 3 missteps. It really helps protect our guys against STP and bolt. I also thought bl 2 Daze is the sweet spot because it forces respect but our hand won’t get clogged by it. I’ll do some more testing and reply with a better deck list tonight. However, so far I’ve found Gush to be underwhelming. With too many draw spells and lower creature density, I almost feel like we’re just being a worse “blue” deck as opposed to a tempo/aggro deck that happens to be blue. Here is what I’ve been playing:

@naixin I was actually just going to bring up Lotus Petal myself. It definitely conflicts with Null Rod, but I feel like hitting UU is more important in Merfolk than any other deck, including decks built around Mana Drain.

@john-cox Time Walk, a huge portion of the time. Also FoW late game to seal it sometimes. I imagine you could grab Hurk in corner cases, but that's a guess because I don't think I've ever actually played Mystical for Hurk while running Merfolk in my life.

@john-cox Time Walk is absolutely brutal in our deck. I even considered a Temporal Tresspass before tearing and realizing it wasn’t too good. I haven’t found dismember to be that good because we can usually race mentor/pyromancer with island walk + TNN. We also get bigger than shops pretty fast.

@Topical_Island Gush is ok, but it hasn’t been as insane in other decks where you can pitch the 2 lands. Brainstorm may be good. Maybe a maindeck dismember can be good as well. I’ve also considered misdirection, Flusterstorm, another creature, or another null rod/damping Sphere.

I think Merfolk Trickster is a card worth testing. Maybe a 2-of to start. What do you cut? Maybe a removal spell; maybe a daze or MM. The fact that this card has flash is an underestimated ability that can put this over the top.

@ssasala I like how you said to test it. I can't argue with that. Testing is great.

My personal read/prediction is that it probably doesn't go in, but that is entirely based on metagame. As soon as I read your post I do what I always do, go check the data... (because I'm not a good magic player, I'm just a guy using stats to mimic one as closely as possible.)

I'm looking to see what we could tap or ambush in the format, and I'm not really seeing it. Blightsteel? I guess that's the best example. Or maybe Griselbrand, Inferno Titan, Emrakul. Ok. Gris is the best example. But now lets run numbers:

19% of decks in the last 4 months are Oath decks. Of those, all but one is running at least 1 copy of Inferno Titan. I can think of lines where this would really help against a Titan. But in most of those cases, something like FoW or another Lord seems much better. Because we need to get our team to 4 toughness pronto or, cooked fish for dinner. I can see in corner cases, where we tap down and swing in for lethal, but remember we likely have islandwalk, so tapping down probably isn't better and might be worse than a Lord if we needed the extra power to go lethal.

I also don't see where flash helps us that much. In this deck we basically want to be tapping all our mana every turn and filling the board with a whole boat full of fish. So we aren't really in the business of holding up mana on their turn. We could wait and play Trickster on their endstep, but I'm not seeing a ton of common situations where that would be better than just tapping out on our turn to play a fish as is our normal plan.

My guess offhand is that in this metagame, this slot is probably better filled by a Phantasmal Image, or a Merfolk Reejery.

I'm glad to hear you'll test this though. This is a hard one to predict, since it there for a whole bag full of corner case value. Those situations might happen once every 5 games, or twice every game. I can't tell. So lets see how it goes.